Redoing my exhaust manifold gasket, and my upper exhaust pipe turned out to be in much worse condition than expected. It has a pretty beefy dent right before the flange. I also discovered that the shop who replaced the entire exhaust manifold last year did not use any kind of donut gasket on the flange. Anyway I bought a new upper exhaust pipe, the problem is I'm not sure how the old one was joined to the catalytic converter as there was no clamp. I cut the exhaust pipe out, ands this is what I'm left with:


I don't have any welding equipment, but I'm hoping I can get the car back together tomorrow. Here are the measurements of the pipes:

New exhaust pipe: 2.5" Outer, 2.4 inner
Cat connecting pipe(above): 2.57-2.63" outer depending on where you measure. The end's inner diameter is only 2.24", I think because it has some of the old pipe stuck inside as well.

What is the best way to combine these? I would prefer to reattach the exhaust manifold to the flange before I bolt it down to the engine to ensure no cracks in the gasket form from it flexing to reach the flange. That means I need to connect these pipes first, though.

Any help is appreciated!!

 

What you want to do is a bit tricky, that exhaust repair requires fabrication

I do hate welding rusty old exhausts and is one of the very few jobs I pay my mate who is 40 yrs an exhaust shop owner and a wizard with MIG

Anyway, when he broke his arm, and I had to wait for an exhaust repair, due to crap welding from the PO that I didnt want to make worse

I fabricated a thin metal sheet roll, and you would use big hose clamps (or even wire) to hold the whole shebang together. Rivets or exhaust sealant can be used

Its temporary, it may still leak, it lasted me a week or so till he could get me in

That repair needs completing by an experienced exhaust specialist imo, unless you intend to replace more parts

 

You might be able to pickup a 2.5" band clamp at the local store, or do the quick-n-dirty way of making one awg suggested. Example

 

I'm not sure what the picture shows. If, as it looks like it might be that the inlet stub of the cat, that groove round it was caused by overtightening the clamp. In which case all you need to do is remove that piece of the down pipe (with a hammer & chisel you might be able tp collapse it inwards, otherwise 2 or 3 three lengthways cuts & pick out the pieces). You might then get the new down pipe in there, but it'd be better if you can get one of those pipe expanders, to get the stub out to its original, undeformed, size.

Tedious but not difficult, no repairs/welding/expertise necessary although that one special tool will make life much easier.

Of course, I might've completely misread the picture/misunderstood the problem, in which case I'm sorry to have wasted your time.

 

Thanks, I'm going to try cutting it. I assumed it was welded in there but I think you're right, it was just clamped in with a lot of force and now a rusted and seized. I grabbed a pipe expander from advance, hopefully I can put the full exhaust back together in a day

 

I think you've got it. Just "overclamped": and now rusty. You can probably grab the cut edge of the pipe with a visegrip and twist it out. Some heat would help.

Don't use those "U bolt" clamps, get the stepped band clamps. Something like these.

 

without welding, anything will be temporary in my opinion. You may try an old trick of a couple of clamps and a large tomato soup can as a temporary fix.,,,,

 

If your pipe expander doesn't get the crimp out enough to separate the two pieces you could cut the clamped area off ,pull the inner pipe, and it appears you'd have enough to still get the new pipe in there and seal it up with a new band clamp...

 

I can't see that, it's just a sleeve joint.

Please don't weld joints that aren't supposed to be welded, a PO did that when he deleted the cat, now I have a one piece system, which proved to be a real pain when I had to replace the transfer case.

 

Those "U-bolt" clamps are meant to be used where the outer pipe has 3 slots which it just closes up - but Jeep (& they're not alone) don't use them.

Those band clamps are definitely worth the extra $$'s, especially if there's any prospect of needing to break the joint again.

 

opinions......

 

Fair comment, but I'm intrigued as to why, in your opinion, XJ's (& millions of other vehicles) left the factory with exhaust systems only temporarily installed)

 

obvious answer